1. Field of the Invention
The present invention relates to a deceleration indicating system for vehicles whereby upon rapid deceleration of a vehicle, a lamp or lamps are caused to flash on and off or a buzzer is operated to warn, for example, the driver in the following vehicle of the rapid deceleration and thereby to prevent the occurrence of rear-end collision, etc.
2. Description of the Prior Art
At present, rear-end collisions account for a large part of the vehicle accidents occurred in the city districts. This appears to have been caused by the fact that the proceeding vehicle signals its driving conditions to the following vehicle by means of the red lamp or lamps which are lighted when the brake pedal is depressed, namely, the stop lights which light up independently of the deceleration rate of the proceeding vehicle are the only available means for ascertaining its driving conditions. In other words, only a slight depression of the brake pedal can cause the lighting of the stop lamps which are the only means for signaling the driving conditions of the proceeding vehicle to the following vehicle. At present, there are two general types of switches used for operating the stop lamp or lamps: (1) a displacement switch in which a microswitch or the like is operated when the amount of depression of the brake pedal exceeds a specified value, and (2) a hydraulic switch which is operated when the brake fluid pressure exceeds a specified value. However, since these switches are operated independently of the magnitude of the force applied to depress the brake pedal, none of these switches is considered satisfactory from safety point of view in terms of the ability to inform the following vehicle of the degree of danger involved. Some driver in the following vehicle is fatigued with unnecessary attentions caused by the operation of the lamps on the proceeding vehicle. Further, when the driver of a first vehicle applies the brakes unnecessarily, there is the danger of the driver of a second following vehicle quickly applying the brakes and causing the second following vehicle itself to be struck from behind by another vehicle.
Still further, if the driver of the following vehicle gets used to the frequent operations of the brake lights on the proceeding vehicle, even if the driver of the proceeding vehicle applies the brakes quickly and the resultant lighting of the brake lamps is observed by the driver of the following vehicle, this cannot arouse much attention of the following vehicle's driver giving rise to the danger of rear-end collision.
Thus, there has existed a need for an improved deceleration indicating system which can replace the conventional systems and by which when the driver of the proceeding vehicle really senses danger and quickly applies the brakes, the driver of the following vehicle can be positively informed of this danger.